There have been Black Panther's throughout history. Here is the line of known Black Panthers in the Marvel 616 Universe.

Bashenga - The original Black Panther
Bashenga was given the secrets of the Panther god Baal. Bashenga creates the Panther Cult to solidify his power. As part of the secrets of Baal Bashenga learns of the mystical heart shaped herb that gives the Panthers their powers.

Unknown number of Black Panthers

Azzuri the Wise - Father of T'Chaka

T'Chaka - Son of Azzuri

S'yan - Son of Azzuri - Younger brother of T'Chaka

T'Challa - Son of T'ChakaErik Killmonger - Takes on mantle for a time

Kasper Cole - AKA Vin Diesel Panther takes over mantle for a short while in NYC